Bacterial gastroenteritis is inflammation of the stomach and intestines that results in acute diarrhea (3 or more episodes per day) lasting less than 14 days and may also include symptoms such as nausea, vomiting, and abdominal cramping. See Thielman and Guerrant, The New England Journal of Medicine, 350:38-47, 2004. In the United States it is estimated that there are >200 million cases of diarrheal illness per year resulting in 73 million physician consultations, 1.8 million hospitalizations, and up to 6000 deaths. See Thielman and Guerrant, supra; Guerrant et al., Clinical Infectious Diseases, 32:331-350, 2001. According to the Centers for Disease Control Food Net data (data compilation from 10 state health departments), in 2010 the number of reported infections and incidence per 100,000 population included the following: Salmonella (8256; 17.6), Campylobacter (6365; 13.6), and Shigella (1780; 3.8). See Centers for Disease Control and Prevention. [Vital Signs: Incidence and Trends of Infection with Pathogens Transmitted Commonly Through Food—Foodborne Diseases Active Surveillance Network, 10 U.S. Sites, 1996-2010]. MMWR Jun. 10, 2011; 60 (22): [749-755]. These three bacteria are the most common cause of bacterial gastroenteritis. The populations most at risk due to bacterial gastroenteritis infection are children (≤5), the elderly, and immunocompromised. Infection, however, can occur in all age groups. The mode of infection is via the fecal-oral route typically from ingesting contaminated food or water or as a result of poor hygiene (hand-washing).
Salmonella are gram-negative, aerobic, rod-shaped bacilli. There are two species of Salmonella including enterica and bongori. Salmonella enterica is further divided into six subspecies with only a fraction of Salmonella enterica subspecies I being responsible for human illness. See Sabbagh et al., FEMS Microbiol Lett 305:1-13, 2010. Salmonella serotypes Typhimurium, Enteritidis, and Newport account for about half of the culture-confirmed Salmonella isolates in the U.S. Salmonella serotype Typhi, the strain that causes typhoid fever, is uncommon in the U.S. while Salmonella serotypes Mississippi and Javiana have been increasingly identified as a source of illness. See Centers for Disease Control and Prevention. [Summary of Notifiable Diseases—United States, 2008]. Published Jun. 25, 2010 for MMWR 2008; 57 (No. 54):[15-16].
Campylobacter are curved, motile, microaerophilic, gram-negative rods. They exhibit rapid, darting motility in a corkscrew fashion using one or two flagella and also have a lipopolysaccharide endotoxin. Two species of Campylobacter, C. jejuni and C. coli, are responsible for the vast majority of human infections. See Klena et al., Journal of Clinical Microbiology, 42:5549-5557, 2004; Poly and Guerry, Current Opinion in Gastroenterology 24:27-31, 2008; Granato et al., Journal of Clinical Microbiology, 48:4022-4027, 2010.
Shigella are gram-negative, aerobic, rod-shaped bacteria that are closely related to E. coli. See Liu et al., FEMS Microbiol. Rev. 32:627-653, 2008. There are four species of Shigella, all of which can cause disease in humans and include S. sonnei (subgroup D), S. flexneri (subgroup B), S. boydii (subgroup B), and S. dysenteriae (subgroup A). According to the 2006 Shigella annual summary published by the CDC, S. sonnei is the most prevalent cause of infections at 76%, followed by S. flexneri (14%), S. boydii (1.1%), and S. dysenteriae (0.5%). See Centers for Disease Control and Prevention. Shigella Surveillance: Annual Summary, 2006. Atlanta, Ga.: US Department of Health and Human Services, November 2008.
There is a need to efficiently and sensitively detect the presence of Salmonella, Shigella, and Campylobacter in samples, including biological specimens to provide diagnostic and prognostic information to physicians treating patients suffering from, or suspected of suffering from, bacterial gastroenteritis or related disorders.